Direct vehicle-to-vehicle (V2V) communication may be critical in enabling future Intelligent Transportation Systems (ITS). Governments in developed nations around the world are investing heavily in ITS to develop traffic-related safety technologies, while the telecom industry and car manufacturers are jointly working to develop in-vehicle infotainment services. To this end, future vehicles on the road may be equipped with radio units that exchange real-time information to avoid collisions, mitigate traffic jams, or reduce fuel consumption. The Federal Communications Commission (FCC) has mandated 75 MHz of spectrum in the 5.85-5.925 GHz band to be allocated for dedicated short-range communications (DSRC) intended to provide V2V communication coverage within a 300 meter range. The IEEE 802.11 p standard has been proposed for DSRC, and it may use orthogonal frequency division multiplexing (OFDM) at the physical (PHY) layer.
Previous works on non-stationary signal processing have dealt with time-series analysis and forecasting. (See Flandarin et al., Recent Advances in Theory and Methods for Nonstationary Signal Analysis, EURASIP J. ADV. SIG. PROC January 2011.) Also, in A Sampling Theorem for Nonstationary Random Process, IEEE T. INF. THY., V. 18, i. 6, pp. 808-809, November 1972, Gardener generalized Nyquist sampling theorem to propose a sampling rate that is two times the maximum frequency present in the double Fourier transform of the autocorrelation function of non-stationary stochastic process. However, the sampling rate proposed by Gardener may be too conservative as it is based upon an extreme case frequency. In a V2V channel, the locally maximum frequency may vary significantly as a vehicle moves into different terrains, such as city downtowns, suburban areas, highways, or country roads. If pilot symbols were inserted at the rate proposed by Gardener, then the channel may get over-sampled, which may be very inefficient in terms of spectral efficiency.
The present embodiments, inter alia, may avoid over sampling, reduce wastage of bandwidth, overcome other challenges associated with V2V wireless communications, and/or otherwise facilitate enhanced V2V wireless communications.